Electrospinning apparatus and electrospinning method

Abstract

To provide an electrospinning apparatus capable of appropriately reducing the concentration of solvent vapor of a raw material liquid in a region where the raw material liquid is ejected from a spinning head.SOLUTION: An electrospinning apparatus in an embodiment includes a conveying part, a spinning head and an air ejection part. In the conveying part, a conveying object is conveyed along the conveying direction, and the spinning head can eject a raw material liquid toward the conveying part from a first direction crossing the conveying direction. The air ejecting part ejects air toward the conveying part from one side of a second direction crossing both the conveying direction and the first direction, thereby forming a flow of air flowing across the conveying part to the opposite region across the conveying part in the second direction.SELECTED DRAWING: Figure 2

Description

Technical Field

[0005]

[0001] Embodiments of the present invention relate to an electrospinning apparatus and an electrospinning method.

Background Art

[0002] An electrospinning apparatus for forming a fiber membrane is used by an electrospinning method (which may also be referred to as a charge-induced spinning method, etc.). When forming a fiber membrane using an electrospinning apparatus, by the electrospinning method, a raw material solution is ejected from the nozzles of one or more spinning heads toward a conveyance target conveyed in a conveyance unit. As a result, fibers of the polymer material contained in the raw material solution are deposited on the surface of the conveyance target, and a fiber membrane is formed on the surface of the conveyance target.

[0003] When forming a fiber membrane by the electrospinning method as described above, it is required to reduce the concentration of the solvent vapor in which the solvent contained in the raw material solution has evaporated in the region where the raw material solution is ejected from the spinning head. For this reason, it is required to appropriately ventilate the region where the raw material solution is ejected from the spinning head or the like, and appropriately reduce the concentration of the solvent vapor of the raw material solution in the region where the raw material solution is ejected from the spinning head.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem that this invention aims to solve is to provide an electrospinning apparatus and an electrospinning method that can appropriately reduce the concentration of solvent vapor in the raw material liquid in the region from which the raw material liquid is ejected from the spinning head. [Means for solving the problem]

[0006] According to this embodiment, the electrospinning apparatus includes a transport section and a spinning head. 、 Air nozzle and air suction section The system is equipped with the following: In the conveying section, the material to be conveyed is conveyed along the conveying direction, and the spinning head is capable of ejecting the raw material liquid toward the conveying section from a first direction intersecting the conveying direction in the conveying section. The air ejection section ejects air toward the conveying section from one side of a second direction intersecting both the conveying direction and the first direction, thereby forming an airflow that crosses the conveying section to the area on the opposite side of the conveying section in the second direction. The air suction unit sucks in air that has flowed across the conveying unit in the second direction, towards the area opposite to the air ejection unit, with the conveying unit in between. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic diagram showing the electrospinning apparatus according to the first embodiment, with the conveying section and the like viewed from one side in the second direction. [Figure 2] Figure 2 is a schematic diagram showing the electrospinning apparatus according to the first embodiment, with the conveying section and other components viewed from the upstream side of the conveying section. [Figure 3] Figure 3 is a schematic diagram showing the electrospinning apparatus according to the first embodiment, with the conveying section and the like viewed from one side in the first direction. [Figure 4] Figure 4 is a schematic diagram showing the electrospinning apparatus according to the first modified example, with the conveying section and other components viewed from one side in the first direction. [Figure 5] Figure 5 is a schematic diagram showing the electrospinning apparatus according to the second modified example, with the conveying section and other components viewed from one side in the first direction. [Figure 6] Figure 6 is a schematic diagram showing the electrospinning apparatus according to the third modified example, with the conveying section and other components viewed from one side in the first direction. [Modes for carrying out the invention]

[0008] The embodiments will be described below with reference to the drawings.

[0009] (First Embodiment) Figures 1, 2, and 3 show an example of an electrospinning apparatus 1 according to the first embodiment. As shown in Figures 1 to 3, a transport path 2 for the transport object 10 is formed in the electrospinning apparatus 1. The transport path 2 extends from a discharge section (not shown) to a winding section (not shown), and the transport object 10 is transported from the discharge section to the winding section, for example, in a roll-to-roll manner. The transport object 10 is a base material or a collected material. In the example shown in Figures 1 to 3, guide rollers 11 and 12 are arranged in the transport path 2, and a transport section 3 is formed between the guide rollers 11 and 12 as part of the transport path 2.

[0010] In the conveying section 3, the object to be conveyed 10 is conveyed from the guide roller 11 toward the guide roller 12, and the direction toward the guide roller 12 is defined as the conveying direction (direction indicated by arrow Z1). Furthermore, in the conveying section 3, the side toward the guide roller 12 is defined as the downstream side, and the side toward the guide roller 11 (arrow Z2 side) is defined as the upstream side. Furthermore, the transport unit 3 is defined by a first direction intersecting the transport direction (indicated by arrows X1 and X2), and a second direction intersecting both the transport direction and the first direction (indicated by arrows Y1 and Y2). The first direction is also referred to as the depth direction of the transport unit 3, and the second direction is also referred to as the width direction of the transport unit 3. Figure 1 shows the transport unit 3 as viewed from one side in the second direction, Figure 2 shows the transport unit 3 as viewed from the upstream side of the transport unit 3, and Figure 3 shows the transport unit 3 as viewed from one side in the first direction.

[0011] In the example shown in Figures 1 to 3, the first direction is perpendicular or approximately perpendicular to the conveying direction in the conveying unit 3, and the second direction is perpendicular or approximately perpendicular to both the conveying direction and the first direction. Also in the example shown in Figures 1 to 3, the conveying direction in the conveying unit 3 is parallel or approximately parallel to the vertical direction, and the object to be conveyed is conveyed vertically downward in the conveying unit 3. Furthermore, the first and second directions are parallel or approximately parallel to the horizontal plane. Note that the conveying direction in the conveying unit 3 is not particularly limited. In one example, the object to be conveyed 10 is conveyed vertically upward in the conveying unit 3. In another example, the conveying direction in the conveying unit 3 is parallel or approximately parallel to the horizontal direction (horizontal plane). In yet another example, the conveying direction in the conveying unit 3 is inclined with respect to both the vertical and horizontal directions.

[0012] In the electrospinning apparatus 1, one or more spinning heads 5 are provided corresponding to the transport section 3. In the example shown in Figures 1 to 3, eight spinning heads 5 are provided corresponding to the transport section 3. Four of the eight spinning heads 5, known as spinning heads 5A, are positioned on one side of the transport section 3 in the first direction (the depth direction of the transport section 3), while the remaining four spinning heads 5B are positioned on the opposite side of the transport section 3 from the spinning heads 5A in the first direction. In the example shown in Figures 1 to 3, the four spinning heads 5A are arranged side by side in the transport direction of the transport section 3 in the region on one side of the transport section 3 in the first direction. The four spinning heads 5B are arranged side by side in the transport direction of the transport section 3 in the region opposite to the spinning heads 5A in the transport section 3 in the first direction. The number of spinning heads 5 provided in the transport section 3 is not particularly limited, as long as there is one or more.

[0013] Each spinning head 5 is equipped with one or more nozzles 6, and in the example shown in Figures 1 to 3, each spinning head 5 is provided with multiple nozzles 6. Each nozzle 6 of each spinning head 5 protrudes outward from its outer surface. Each nozzle 6 of each spinning head 5 protrudes toward the side where the conveying unit 3 is located in the first direction. Each spinning head 5 is capable of ejecting raw material liquid from each nozzle 6 toward the conveying unit 3, and is capable of ejecting raw material liquid toward the conveyed object 10 that is conveyed by the conveying unit 3. The number of nozzles 6 provided on each spinning head 5 is not particularly limited, as long as there is one or more. The shape of the nozzles 6 is also not particularly limited.

[0014] As shown in Figure 2, the electrospinning apparatus 1 includes a raw material liquid supply unit 7 and a power supply 8. The raw material liquid supply unit 7 constitutes the raw material liquid supply source and the raw material liquid supply path from the supply source to each of the spinning heads 5. In one example, the supply unit 7 drives a drive member such as a pump to supply the raw material liquid stored in a tank or the like to each of the spinning heads 5. The supply unit 7 may also be provided with either a control valve capable of controlling the flow rate and pressure of the raw material liquid supplied to each of the spinning heads 5, or a switching valve capable of switching the supply and cessation of the raw material liquid to each of the spinning heads 5.

[0015] The raw material liquid is a solution of a polymer material in a solvent. Therefore, when the raw material liquid is ejected from each of the spinning heads 5 onto the conveyance target 10, the fibers of the polymer material contained in the raw material liquid are deposited on the surface of the conveyance target 10, and a fiber film 13 is formed on the surface of the conveyance target. In one example, the collector is conveyed as the conveyance target 10, and the fiber film 13 is formed on the surface of the collector. Then, by removing the fiber film 13 from the collector, the fiber film 13 is obtained as a product. In another example, the base material is conveyed as the conveyance target 10, and the fiber film 13 is formed on the surface of the base material. Then, a product in which the base material and the fiber film 13 are integrated is obtained. Examples of the product in which the base material and the fiber film 13 are integrated include, but are not limited to, a separator-integrated electrode of a battery or an electrolytic capacitor. In this case, one of the negative electrode (cathode) and the positive electrode (anode) of the electrode group is used as the base material. And the fiber film 13 formed on the surface of the base material becomes a separator integrated with the negative electrode or the positive electrode.

[0016] The polymer contained in the raw material liquid and the solvent for dissolving the polymer are appropriately determined according to the type of fiber to be deposited on the surface of the conveyance target and the like. The polymer material is not particularly limited and can be appropriately changed according to the material of the fiber to be formed. Examples of the polymer material include, for example, polypropylene, polyethylene, polystyrene, polyethylene terephthalate, polyvinyl chloride, polycarbonate, nylon, aramid, polyamideimide, polyimide, etc. The solvent used in the raw material liquid may be any one that can dissolve the polymer substance. The solvent can be appropriately changed according to the polymer substance to be dissolved. Examples of the solvent include, for example, water, methanol, ethanol, isopropyl alcohol, acetone, benzene, toluene, N-methyl-2-pyrrolidone (NMP), and dimethylacetamide (DMAc), etc.

[0017] The power supply 8 applies a voltage of a predetermined polarity to each of the spinning heads 5. In this case, a voltage of the same polarity is applied to each of the multiple spinning heads 5. At each of the spinning heads 5, the voltage is applied by the power supply 8 as described above, and the raw material solution is supplied by the supply unit 7, so that the raw material solution becomes charged with the same polarity as the applied voltage. The polarity of the voltage applied from the power supply 8 to the spinning heads 5 may be positive or negative. That is, at each of the spinning heads 5, the raw material solution may be charged with a positive polarity or a negative polarity. In the example shown in Figure 2, the entire spinning head 5 is formed from a conductive material, and a voltage of a predetermined polarity is applied to the entire spinning head 5. Then, at each of the spinning heads 5, the supplied raw material solution becomes charged with the same polarity as the applied voltage. Also, in the example shown in Figure 2, the power supply 8 is a DC power supply, and at each of the spinning heads 5, the raw material solution is charged with a positive polarity.

[0018] In another example, in each spinning head 5, only the nozzle 6 is made of a conductive material, while the parts other than the nozzle 6 are made of a non-conductive material. Then, in each spinning head 5, a voltage of a predetermined polarity is applied to the nozzle 6, and the supplied raw material is charged to the same polarity as the nozzle 6. In yet another example, a conductive part is formed in either the raw material supply source to each spinning head 5, or in the raw material supply path between the supply source and each spinning head 5, and a voltage of a predetermined polarity is applied to the conductive part by a power supply 8. Then, the raw material is charged to the same polarity as the conductive part to which the voltage is applied. In this case, the raw material charged to the predetermined polarity is supplied to each spinning head 5.

[0019] In one example, the object to be conveyed 10 conveyed in the conveying unit 3 is grounded. In another example, instead of grounding the object to be conveyed 10, a voltage of the opposite polarity to each of the spinning heads 5 is applied to the object to be conveyed 10 by the power source 8 or a power source different from the power source 8. In the present embodiment, as described above, by applying a voltage by the power source 8, the raw material liquid supplied to each of the spinning heads 5 is charged to a predetermined polarity. Therefore, a potential difference occurs between the raw material liquid supplied to each of the spinning heads 5 and the object to be conveyed 10, and due to the generated potential difference, the raw material liquid is ejected from each nozzle 6 of the spinning head 5 toward the object to be conveyed 10.

[0020] As described above, in the present embodiment, by the electrospinning method (also referred to as a charge induction spinning method, etc.), the raw material liquid is ejected from each of the spinning heads 5 toward the object to be conveyed 10, and the fiber film 13 is formed on the surface of the object to be conveyed 10. The magnitude of the voltage applied to the spinning head 5 or the like by the power source 8 is appropriately set corresponding to the types of the solvent and solute in the raw material liquid, the boiling point and vapor pressure curve of the solvent of the raw material liquid, the concentration and temperature of the raw material liquid, the shape of the nozzle 6, and the distance between the object to be conveyed 10 (conveying unit 3) and the nozzle 6. Further, the ejection speed of the raw material liquid from each nozzle 6 of the spinning head 5 is set to a magnitude corresponding to the concentration, viscosity and temperature of the raw material liquid, the voltage applied to the spinning head 5 or the like, and the shape of the nozzle 6.

[0021] Also, in one example of FIGS. 1 to 3, each of the spinning heads 5A ejects the raw material liquid toward the object to be conveyed 10 from one side in the first direction (the depth direction of the conveying unit 3). And each of the spinning heads 5B ejects the raw material liquid toward the object to be conveyed 10 from the side opposite to the spinning head 5A in the first direction. Therefore, in one example of FIGS. 1 to 3, the raw material liquid is ejected toward the object to be conveyed 10 conveyed in the conveying unit 3 from both sides in the first direction. Accordingly, the raw material liquid is ejected onto both surfaces of the object to be conveyed 10, and the fiber film 13 is formed on both surfaces of the object to be conveyed 10. In one example, the raw material liquid may be ejected only onto one surface of the object to be conveyed 10 conveyed in the conveying unit 3. In this case, the fiber film 13 is formed only on one surface of the object to be conveyed 10.

[0022] The electrospinning apparatus 1 also includes an air ejection unit 15, an air suction unit 16, and a control unit (controller) 17. The air ejection unit 15 is positioned on one side of the conveying unit 3 in the second direction (the width direction of the conveying unit 3). When activated, the air ejection unit 15 ejects air toward the conveying unit 3, for example, by ejecting dry air. As a result, air is ejected from one side of the conveying unit 3 in the second direction by the air ejection unit 15. Furthermore, as air is ejected from the air ejection unit 15 as described above, an airflow (arrow F1) is formed that crosses the conveying unit 3 and flows to the area on the opposite side (the other side) of the conveying unit 3 in the second direction.

[0023] In this embodiment, the air suction unit 16 is positioned on the opposite side of the transport unit 3 from the air ejection unit 15 in the second direction, and is located in the region opposite to the air ejection unit 15 across the transport unit 3 in the second direction. Therefore, the air suction unit 16 is located in the region where air from the air ejection unit 15 flows across the transport unit 3. When activated, the air suction unit 16 sucks in the air that has flowed across the transport unit 3 to the region opposite to the air ejection unit 15 across the transport unit 3 in the second direction. In an example such as Figure 3, the air suction unit 16 faces the air ejection unit 15 across the transport unit 3 in the second direction (width direction of the transport unit 3).

[0024] In this embodiment, the air suction unit 16 is activated when the air ejection unit 15 is activated. When the air ejection unit 15 and the air suction unit 16 are activated, the flow direction of the air (arrow F1) that flows across the conveying unit 3 to the area opposite the air ejection unit 15, with the conveying unit 3 in between, becomes parallel or approximately parallel to the second direction. Here, a virtual plane H is defined that is perpendicular or approximately perpendicular to the conveying direction in the conveying unit 3. In this embodiment, the flow direction of the air flowing across the conveying unit 3 formed by the operation of the air ejection unit 15 and the air suction unit 16 is parallel or approximately parallel to the virtual plane H, and the angle that the flow direction makes with respect to the virtual plane H is 0° or approximately 0°. Note that in an example such as Figure 3, the downward vertical side of the conveying unit 3 is the conveying direction, so the virtual plane H is a horizontal plane.

[0025] The control unit (controller) 17 is, for example, a computer. The control unit 17 includes a processor or integrated circuit (control circuit) including a CPU (Central Processing Unit), ASIC (Application Specific Integrated Circuit), or FPGA (Field Programmable Gate Array), and a storage medium such as memory. The control unit 17 may have only one integrated circuit or may have multiple integrated circuits. The control unit 17 performs processing by executing a program stored in the storage medium. The control unit 17 controls the supply of raw material liquid to each of the spinning heads 5, the transport of the transport objects 10, the application of voltage from the power supply 8, and the operation of the air ejection unit 15 and the air suction unit 16, respectively. In addition, a server in a cloud environment may perform the processing of the control unit 17 instead of a computer. In this case, for example, the processing of the control unit 17 is performed by a virtual processor executing a program stored in cloud memory, etc.

[0026] While the conveying object 10 is being conveyed in the conveying unit 3, the control unit 17 supplies raw material liquid from the supply unit 7 to each of the spinning heads 5, and charges the raw material liquid supplied to each of the spinning heads 5 by applying a voltage from the power supply 8. As a result, while the conveying object 10 is being conveyed in the conveying unit 3, the raw material liquid is ejected onto the conveying object 10 from the first direction (the depth direction of the conveying unit 3). In addition, while the raw material liquid is being ejected onto the conveying object 10 in the conveying unit 3, the control unit 17 activates the air ejection unit 15, and the air ejection unit 15 ejects air toward the conveying unit 3 from one side in the second direction. As a result, while the raw material liquid is being ejected onto the conveying object 10 in the conveying unit 3, an airflow is formed that crosses the conveying unit 3 in the second direction, in the area opposite to the air ejection unit 15, with the conveying unit 3 in between.

[0027] In this embodiment, the control unit 17 operates the air suction unit 16 in parallel with the operation of the air ejection unit 15. As a result, air that has flowed across the transport unit 3 to the area opposite to the air ejection unit 15 in the second direction is sucked in by the air suction unit 16. In this embodiment, the control unit 17 adjusts the amount and speed of air ejected from the air ejection unit 15 by controlling the operation of the air ejection unit 15. The control unit 17 also adjusts the amount and speed of air sucked in the air suction unit 16 by controlling the operation of the air suction unit 16.

[0028] Furthermore, when the raw material liquid is ejected from each of the spinning heads 5 toward the conveyed object 10 being conveyed in the conveying section 3, solvent vapor is generated in the region from which the solvent contained in the raw material liquid is ejected. As shown in Figure 1, etc., in this embodiment, the electrospinning apparatus 1 is equipped with detectors 18. Each detector 18 detects the concentration of solvent vapor of the solvent contained in the raw material liquid. In the example shown in Figure 1, etc., four detectors 18 are provided, and each detector 18 is positioned between two corresponding spinning heads 5 that are adjacent to each other in the conveying direction in the conveying section 3.

[0029] The number of detectors 18 is limited to one or more, and the position in which the detectors 18 are placed is not particularly limited as long as it is in or near the transport unit 3. In other words, one or more detectors 18 should be placed in or near the area in which the raw material liquid is ejected from the spinning head 5. However, the detectors 18 should be placed in a position that does not obstruct the ejection of the raw material liquid from each of the spinning heads 5 to the transported material 10. In one example, the detector 18 is placed adjacent to the spinning head 5 located furthest upstream in the transport unit 3, from the upstream side of the transport unit 3. In another example, the detector 18 is placed adjacent to the spinning head 5 located furthest downstream in the transport unit 3, from the downstream side of the transport unit 3. In yet another example, the detector 18 is placed between the air ejection unit 15 and the air suction unit 16 in the second direction (the width direction of the transport unit 3), and the detector 18 is adjacent to the transport unit 3 from one side in the second direction.

[0030] In this embodiment, the control unit 17 acquires the detection result from the detector 18. Based on the detection result from the detector 18, the control unit 17 calculates the concentration of solvent vapor of the solvent contained in the raw material liquid in the region where the raw material liquid is ejected from the spinning head 5. Based on the calculated solvent vapor concentration, the control unit 17 adjusts the amount and speed of air ejected from the air ejection unit 15. The control unit 17 may also adjust the amount and speed of air suction from the air suction unit 16 based on the calculated solvent vapor concentration. In one example, the control unit 17 determines whether the calculated solvent vapor concentration is above a reference value. If the solvent vapor concentration is above a reference value, the control unit 17 increases at least one of the amount and speed of air ejected from the air ejection unit 15 from the real-time state. At this time, at least one of the amount and speed of air suction from the air suction unit 16 may also be increased from the real-time state.

[0031] In this embodiment, each of the spinning heads 5 is capable of ejecting the raw material liquid toward the conveying section 3 from a first direction. The air ejection section 15 ejects air toward the conveying section 3 from one side in a second direction, thereby forming an airflow that crosses the conveying section 3 and flows to the area on the opposite side (the other side) of the conveying section 3 from the air ejection section 15. When the raw material liquid is ejected from each of the spinning heads 5 toward the conveyed material 10 in the conveying section 3, the airflow is formed as described above, and the solvent vapor of the solvent contained in the raw material liquid flows together with the air from the air ejection section 15 toward the area on the opposite side of the conveying section 3 from the air ejection section 15. As a result, the conveying section 3 and its vicinity, i.e., the area from which the raw material liquid is ejected from the spinning heads 5, are properly ventilated, and the concentration of solvent vapor in the raw material liquid is appropriately reduced in the area from which the raw material liquid is ejected from the spinning heads 5.

[0032] By appropriately reducing the concentration of solvent vapor in the region where the raw material liquid is ejected from the spinning head 5, solvent droplets contained in the raw material liquid are less likely to remain on the surface of the conveyed object 10. As solvent droplets are less likely to remain on the surface of the conveyed object 10, even if the amount of raw material liquid ejected from each of the spinning heads 5 is increased, the formation of solvent droplets in the fiber film 13 on the surface of the conveyed object 10 is appropriately suppressed. Therefore, even if the amount of raw material liquid ejected from each of the spinning heads 5 is increased, a fiber film 13 with no or very few solvent droplets is appropriately formed on the surface of the conveyed object 10.

[0033] Furthermore, in this embodiment, the air suction unit 16 sucks in the air that flows across the conveying unit 3 to the area opposite the air ejection unit 15, with the conveying unit 3 in between, in the second direction. The air suction unit 16 is positioned in the area opposite the air ejection unit 15, with the conveying unit 3 in between, in the second direction. This allows for a more appropriate airflow across the conveying unit 3 in the second direction. As a result, the area from which the raw material liquid is ejected from the spinning head 5 is more appropriately ventilated, and the concentration of solvent vapor in the raw material liquid in the area from which the raw material liquid is ejected from the spinning head 5 is more appropriately reduced. In this embodiment, the detector 18 detects the concentration of solvent vapor from the evaporated solvent contained in the raw material liquid. Based on the detection result from the detector 18, the control unit 17 calculates the concentration of solvent vapor in the region from which the raw material liquid is ejected from the spinning head 5. Based on the calculated concentration of solvent vapor, the control unit 17 adjusts the amount and velocity of air ejected from the air ejection unit 15, and / or the amount and velocity of air sucked in from the air suction unit 16. As a result, the flow rate and velocity of air crossing the transport unit 3 are appropriately adjusted in accordance with the concentration of solvent vapor in the region from which the raw material liquid is ejected. Therefore, the region from which the raw material liquid is ejected from the spinning head 5 is more appropriately ventilated, and the concentration of solvent vapor in the raw material liquid is further appropriately reduced in the region from which the raw material liquid is ejected from the spinning head 5.

[0034] (modified version) In the embodiments described above, the flow direction of the airflow crossing the conveying section 3 in the second direction (width direction of the conveying section 3) is parallel or substantially parallel to the virtual plane H, but is not limited to this. In the first modified example shown in Figure 4, the flow direction of the airflow crossing the conveying section 3 in the second direction is inclined upstream of the conveying section 3 with respect to the virtual plane H. In the second modified example shown in Figure 5, the flow direction of the airflow crossing the conveying section 3 in the second direction is inclined downstream of the conveying section 3 with respect to the virtual plane H. In Figures 4 and 5, the conveying section 3 and the like are shown as viewed from one side in the first direction.

[0035] In both the first and second modifications, similar to the embodiments described above, the air ejection unit 15 ejects air from one side in the second direction toward the conveying unit 3, thereby forming an airflow that crosses the conveying unit 3 and flows to the area opposite the air ejection unit 15 in the second direction, with the conveying unit 3 in between. Therefore, in both modifications, similar to the embodiments described above, the conveying unit 3 and its vicinity, i.e., the area from which the raw material liquid is ejected from the spinning head 5, are properly ventilated, and the concentration of solvent vapor in the raw material liquid is appropriately reduced in the area from which the raw material liquid is ejected from the spinning head 5. Consequently, both modifications produce the same functions and effects as the embodiments described above.

[0036] Here, in the first modified example in Figure 4, we define the inclination angle θa such that the direction of flow crossing the conveying section 3 is inclined upstream of the conveying section 3 with respect to the virtual plane H. The inclination angle θa is 60° or less. Also, in the example in Figure 4, the vertically downward side is the conveying direction in the conveying section 3. Therefore, in the example in Figure 4, the inclination angle θa corresponds to the elevation angle, which is the inclination angle vertically upward with respect to the horizontal plane. Also, in the second modified example in Figure 5, we define the inclination angle θb such that the direction of flow crossing the conveying section 3 is inclined downstream of the conveying section 3 with respect to the virtual plane H. The inclination angle θb is 60° or less. Also, in the example in Figure 5, the vertically downward side is the conveying direction in the conveying section 3. Therefore, in the example in Figure 5, the inclination angle θb corresponds to the depression angle, which is the inclination angle vertically downward with respect to the horizontal plane.

[0037] Furthermore, in the embodiments described above, the air suction unit 16 is positioned in the region opposite to the air ejection unit 15 with the transport unit 3 in between in the second direction, but it is not limited to this. In the third modified example shown in Figure 6, the transport object 10 is transported vertically downward in the transport unit 3, and the air suction unit 16 is positioned at a location vertically downward relative to the transport unit 3. That is, the air suction unit 16 is positioned at a location away from the transport unit 3 in a direction that intersects both the first and second directions.

[0038] In this modified example, the air ejection unit 15 ejects air from one side of the second direction toward the conveying unit 3, thereby forming an airflow (arrow F1) that crosses the conveying unit 3 to the area opposite the air ejection unit 15 in the second direction. However, in this modified example, the air suction unit 16 is operated in parallel with the operation of the air ejection unit 15, so the air that crosses the conveying unit 3 in the second direction flows vertically downward from the area opposite the air ejection unit 15 in the second direction, across the conveying unit 3 (arrow F2). That is, air flows toward the air suction unit 16 from the area opposite the air ejection unit 15 in the second direction, across the conveying unit 3, along a direction that intersects both the first and second directions.

[0039] In this modified example, as with the embodiments described above, an airflow is formed that crosses the transport section 3 in the second direction, flowing to the area opposite the air ejection section 15, with the transport section 3 in between. Therefore, in this modified example, as with the embodiments described above, the transport section 3 and its vicinity, i.e., the area from which the raw material liquid is ejected from the spinning head 5, are properly ventilated, and the concentration of solvent vapor in the raw material liquid is appropriately reduced in the area from which the raw material liquid is ejected from the spinning head 5. Thus, this modified example also produces the same functions and effects as the embodiments described above.

[0040] Furthermore, in one example of an electrospinning apparatus 1, the transport path 2 alternately arranges transport sections in which the object to be transported 10 is transported vertically downward, as shown in the transport section 3 of the example in Figures 1 to 3, and transport sections in which the transport direction of the object to be transported 10 is vertically upward, opposite to the transport section 3 of the example in Figures 1 to 3. Then, in each of the transport sections where the transport direction is vertically downward and where the transport direction is vertically upward, one or more spinning heads 5 spray the raw material liquid toward the object to be transported 10 from a first direction (the depth direction of the transport section) that intersects (orthogonal or nearly orthogonal to) the transport direction, similar to the embodiments described above.

[0041] Then, in each of the conveying sections, similar to the embodiments described above, dry air is ejected toward the conveying section by the air ejection section 15 from one side of the second direction (the width direction of the conveying section) that intersects (is perpendicular or nearly perpendicular) both the conveying direction and the first direction. As a result, in each of the conveying sections, an airflow is formed that flows across the conveying section to the area opposite the air ejection section 15 in the second direction. Therefore, in the electrospinning apparatus 1, each of the conveying sections and their vicinity are properly ventilated, similar to the embodiments described above. And, similar to the embodiments described above, the concentration of solvent vapor in the raw material liquid is appropriately reduced in each of the conveying sections and their vicinity.

[0042] According to at least one embodiment or example, the spinning head is capable of ejecting the raw material liquid toward the conveying section from a first direction intersecting the conveying direction. The air ejection section ejects air toward the conveying section from one side of a second direction intersecting both the conveying direction and the first direction, thereby forming an airflow that flows across the conveying section to the region on the opposite side of the conveying section in the second direction. This provides an electrospinning apparatus and electrospinning method that can appropriately reduce the concentration of solvent vapor in the raw material liquid in the region from which the raw material liquid is ejected from the spinning head.

[0043] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. The following are additional notes. [1] A conveying unit in which the object to be conveyed is conveyed along the conveying direction, A spinning head capable of ejecting raw material liquid toward the conveying section from a first direction intersecting the conveying direction in the conveying section, An electrospinning apparatus comprising: an air ejection unit that ejects air toward the conveying unit from one side of a second direction intersecting both the conveying direction and the first direction, thereby forming an airflow that crosses the conveying unit and flows to the region opposite the conveying unit in the second direction. [2] The electrospinning apparatus of [1], further comprising an air suction unit for sucking the air that has flowed across the conveying unit into the region opposite to the air ejection unit with respect to the conveying unit in the second direction. [3] The electrospinning apparatus of [2], wherein the air suction unit is located in the region opposite to the air ejection unit with respect to the second direction, with the transport unit in between. [4] A electrospinning apparatus, any one of [1] to [3], further comprising a detector for detecting the concentration of solvent vapor obtained by evaporating the solvent contained in the raw material liquid. [5] The transport unit transports the object to be transported along the transport direction, The raw material liquid is ejected from a first direction intersecting the conveying direction in the conveying section toward the object being conveyed in the conveying section, In a state in which the raw material liquid is being ejected toward the object to be transported, air is ejected toward the transport section from one side of a second direction that intersects both the transport direction and the first direction, thereby forming an airflow that flows across the transport section to the region opposite to the transport section in the second direction. A method for electrospinning that comprises the following: [Explanation of Symbols]

[0044] 1...Electrospinning device, 3...Conveying unit, 5(5A,5B)...Spinning head, 10...Item to be conveyed, 15...Air ejection unit, 16...Air suction unit, 17...Control unit, 18...Detector.

Claims

1. A conveying unit in which the object to be conveyed is conveyed along the conveying direction, A spinning head capable of ejecting raw material liquid toward the conveying section from a first direction intersecting the conveying direction in the conveying section, An air ejection unit that ejects air toward the conveying unit from one side of a second direction intersecting both the conveying direction and the first direction, thereby forming an airflow that crosses the conveying unit and flows to the region opposite to the conveying unit in the second direction, Regarding the second direction, an air suction unit sucks the air that has flowed across the conveying unit to the region opposite to the air ejection unit, with the conveying unit in between. An electrospinning apparatus equipped with the following:

2. The electrospinning apparatus according to claim 1, wherein the air suction unit is arranged in the region opposite to the air ejection unit with the transport unit in between in the second direction.

3. The electrospinning apparatus according to claim 1 or 2, further comprising a detector for detecting the concentration of solvent vapor obtained by evaporating the solvent contained in the raw material liquid.

4. In the transport section, the transport object is transported along the transport direction, The raw material liquid is ejected from a first direction intersecting the conveying direction in the conveying section toward the object being conveyed in the conveying section, In a state in which the raw material liquid is being ejected toward the object to be transported, air is ejected toward the transport section from one side of a second direction that intersects both the transport direction and the first direction, thereby forming an airflow that crosses the transport section and flows to the region on the opposite side of the transport section in the second direction. With respect to the second direction, the air that has flowed across the conveying section is sucked into the region on the opposite side of the conveying section from the side from which the air is ejected, A method for electrospinning that comprises the following:

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